Photosynthesis Chloroplast Structure 3

Question 1

Chloroplasts are thought to have originated through a process called:

Accepted Answer

Endosymbiosis

Answer

The endosymbiotic theory proposes that chloroplasts evolved from ancient cyanobacteria engulfed by a eukaryotic host cell.

Question 2

Which evidence supports the endosymbiotic origin of chloroplasts?

Accepted Answer

They contain their own ribosomes and circular DNA

Answer

Chloroplasts possess prokaryote-like circular DNA and 70S ribosomes, supporting an endosymbiotic ancestry.

Question 3

Stroma lamellae connect adjacent:

Accepted Answer

Grana to each other

Answer

Stroma lamellae are flattened membrane tubes that interconnect individual grana stacks.

Question 4

Which pigment is found in the thylakoid membrane and is primarily responsible for absorbing light in plants?

Accepted Answer

Chlorophyll a

Answer

Chlorophyll a is the primary photosynthetic pigment embedded in the thylakoid membrane of plant chloroplasts.

Question 5

The double membrane surrounding the chloroplast is collectively called the:

Accepted Answer

Chloroplast envelope

Answer

The chloroplast envelope consists of the outer and inner membranes that together bound the organelle.

Photosynthesis Practice Test